2-Methyl-2-acetyl-thiazolidine

ABSTRACT

Novel thiazolidines, a process for their manufacture, and odorant and/or flavorant compositions containing the novel compounds are disclosed.

FIELD OF THE INVENTION

This invention relates to the fields of odorants and/or fragrances.

SUMMARY OF THE INVENTION

The present invention relates to thiazolidines as odorant and/or flavoring substances. More particularly, the invention is concerned with odorant and/or flavoring compositions containing thiazolidines and with a method of imparting an odor and/or flavor to products using thiazolidines. The invention is also concerned with certain thiazolidines per se and a process for the manufacture thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The odorant and/or flavoring compositions provided by the present invention contain as an essential odor- and/or flavor-imparting ingredient a thiazolidine of the general formula ##EQU1## wherein R¹ represents a hydrogen atom and

R² represents an aliphatic C₂₋₁₀ hydrocarbon group (other than a C₃₋₆ isoalkyl group), an aliphatic C₁₋₁₀ hydrocarbon group substituted by a group X, or a group R³ ;

R³ represents an araliphatic C₇₋₁₀ hydrocarbon group, a 5- or 6- membered monocyclic, carbocyclic or heterocyclic aromatic group, a dioxolane group which may be sutstituted or a group --COOR⁴,

X represents an oxo group which may be ketalised or a group --COOR⁴, --SR⁵ or --OR⁵ ;

R⁴ represents a C₁₋₆ alkyl group and R⁵ represents a hydrogen atom or a C₁₋₆ alkyl or C₁₋₆ acyl group or

R¹ and R² each independently represents an aliphatic C₁₋₁₀ hydrocarbon group, which may be substituted by a group X, or a group R³ or

R¹ and R² together represent a --(CH₂)₄₋₇ group.

Aliphatic C₂₋₁₀ hydrocarbon groups can be straight-chain or branched-chain, unsaturated, preferably mono-olefinically unsaturated, or saturated groups. C₃₋₆ isoalkyl groups are the isopropyl, isobutyl, isopentyl and isohexyl groups. Examples of araliphatic C₇₋₁₀ hydrocarbon groups are the benzyl and phenethyl groups. Examples of 5- or 6-membered monocyclic, carbocyclic or heterocyclic aromatic groups are the phenyl, furyl, pyrrolyl, thienyl, imidazolyl, thiazolyl, pyridyl and pyrazyl groups. An example of a dioxolane group which may be substituted is the 2,2-dimethyl-4-dioxolanyl group. A C₁₋₆ acyl group is preferably derived from an aliphatic monocarboxylic acid such as formic acid, acetic acid or propionic acid. Examples of ketalised oxo groups are the dimethoxy, diethoxy, methylenedioxy, ethylenedioxy and phenylenedioxy groups.

Examples of thiazolidines of formula I in which R¹ represents a hydrogen atom are 2-ethyl-, 2-propyl-, 2-butyl-, 2-secbutyl-, 2-pentyl-, 2-hexyl-, 2-heptyl-, 2-(2-methylthioethyl)-, 2-ethoxycarbonyl-, 2-hydroxymethyl-, 2-phenyl-, 2-benzyl-, 2-(2-furyl)- and 2-(2-pyrrolyl)-thiazolidine. Examples of thiazolidines of formula I in which R¹ and R² each independently represent an aliphatic C₁₋₁₀ hydrocarbon group, which may be substituted by a group X, or a group R³ or in which R¹ and R² together represent a --(CH₂)₄₋₇ group are 2-methyl-2-(4-methyl-3-penten-1-yl)-, 2-acetyl-2-methyl-, 2-methyl-2-isopropyl-, 2-(1-hydroxyethyl)-2-methyl-, 2-hydroxymethyl-2-methyl-, 2-ethoxycarbonyl-2-methyl-, 2,2-dimethyl-, 2,2-dipropyl-, 2-ethyl-2-methyl-, 2-hexyl-2-methyl-, 2,2-tetramethylene- and 2,2-pentamethylene-thiazolidine.

A group of novel thiazolidines which are subgeneric to the compounds of formula I referred to earlier, and which also form part of this invention, can be generically formulated thus: ##EQU2## wherein R⁶ represents a hydrogen atom or the methyl, ethyl, ethoxycarbonyl, ethoxycarbonylmethyl or acetoxymethyl group and

R⁷ represents the butyl, secbutyl, pentyl, decyl, 4-methyl-3-pentenyl, dimethoxymethyl, 2-methylthioethyl, 2-furyl, 2-(5-methylfuryl), 2-thienyl, 2-(5-methylthienyl), 2-pyrrolyl, 2-(N-methylpyrrolyl), pyridyl or 4-(2,2-dimethyldioxolanyl) group when R⁶ represents a hydrogen atom; or represents the isopropyl, isobutyl, 4-methyl-3-pentenyl, 1-hydroxyethyl, acetyl, propionyl, acetoxymethyl, 2-(1-acetoxyethyl), 3-hydroxypropyl or 2,2-dimethoxyethyl group when R⁶ represents the methyl group; or represents the butyl or acetyl group when R⁶ represents the ethyl group; or represents the ethoxycarbonyl or 1-ethoxycarbonyl-ethyl group when R⁶ represents the ethoxycarbonyl group; or represents the ethoxycarbonylmethyl group when R⁶ represents the ethoxycarbonylmethyl group; or represents the acetoxymethyl group when R⁶ represents the acetoxymethyl group.

The thiazolidines of formula I or formula II can be manufactured according to known procedures; for example, by condensing cysteamine with a keto compound of the formula R¹ --CO--R² or R⁶ --CO--R⁷. The condensation can be carried out in the presence of, or in the absence of, a solvent. Suitable solvents include water, alcohols such as methanol, ethanol etc, ethers such as diethyl ether, dioxan, tetrahydrofuran etc, hydrocarbons such as benzene, toluene etc, halogenated hydrocarbons such as methylene chloride, chloroform etc, amides such as dimethylformamide etc. Preferred solvents are methanol and ethanol (method A hereinafter) or benzene (method B hereinafter), the condensation proceeding particularly well in the latter case with azeotropic removal of the water which is formed. The molar proportion of cysteamine to keto compound conveniently amounts to 1:1, although one or both condensation components can be employed in excess. Cysteamine can be used as such or in the form of an ammonium salt with an organic or inorganic acid. In the latter case, cysteamine can be liberated in situ by means of a base. It can also be generated in situ from suitable precursors (e.g. from ethyleneimine with hydrogen sulphide).

The keto component can be used as such or in protected form (e.g. as the acetal or ketal), in the latter case the condensation conditions being chosen so that the free keto compound is formed in situ. The condensation is conveniently carried out at a temperature between 0°C and 150°C, preferably between room temperature and the boiling temperature of the solvent used. The duration of the condensation amounts to between about 5 minutes and 24 hours depending on the temperature and reactivity of the keto compound used. The condensation is advantageously carried out in an inert gas atmosphere (e.g. nitrogen or argon).

The isolation of the condensation product can be carried out according to known methods; for example, by concentrating the solution, taking up the residue in an organic extraction agent, washing and drying the organic phase and distillation or by filtering the concentrated solution through aluminium oxide and subsequent distillation.

The thiazolidines of formula I are distinguished by particular fragrance and flavour qualities, different notes in the foreground appearing according to the nature of the substituents in the 2-position. The aroma spectrum of the thiazolidines of formula I can extend from ester like-fruit like, green, mushroom- and vegetable-like (bean, asparagus, onion, radish), through nutty, butter-like, fatty, caramellous to smoky, spicy, meaty or fish-like.

The thiazolidines of formula I can accordingly be used for the aromatization of foodstuffs such as soups, vegetables, sauces etc. The pronounced flavour qualities of the thiazolidines enable them to be used in finished products in small concentrations (e.g. in the range of 0.01-10 ppm, preferably 0.1-1 ppm).

The thiazolidines of formula I can be mixed with usual carrier materials and/or diluents, if desired with other flavour-imparting ingredients and if necessary with emulsifiers, to form aromatizing agents which confer to foodstuffs, for example, a spicy or a vegetable flavour or which intensify such a flavour. The thiazolidines of formula I can, however, also be added alone to the products to be aromatized. In this case, particular attention must be paid, when carrying out the addition, to providing a homogeneous distribution of the thiazolidine in the product to be aromatized. Where the thiazolidines are used as components for the manufacture of artificial aromas, these aromas can be formulated, for example, as liquids, pastes or powders. The products can, for example, be spray-dried, vacuum-dried or lyophilized. The formulation of such artificial aromas as well as the aromatization of foodstuffs can be carried out in a manner which is known per se [see J. Merory; Food flavourings, composition, manufacture and use; Avi Publ. Co. Inc. Westport (1968)].

The following Examples illustrate the manner in which the thiazolidines aforesaid can be prepared:

METHOD A: EXAMPLE 1

37.0 g (0.2 mol) of 6-methyl-hepten-(5)-one-(2) were dissolved in 50 ml of ethanol and treated under an inert gas atmosphere with a solution of 15.43 g (0.2 mol) of cysteamine in 500 ml of ethanol. The mixture was heated for 2 hours under reflux to 100°C. The solution was then concentrated on a rotary evaporator and the residue subjected to a fractional distillation (Widmer column) under a high vacuum. There were obtained 27.38 g (yield 74% of theory) of 2-methyl-2-(4-methyl-3-penten-1-yl)-thiazolidine of boiling point ₀.04 74°-76°C; n_(D) ²⁰ = 1.5150. IR: ν_(max) = 1445, 1378, 790 cm⁻ ¹. Odour: green, sulphurous; flavour: green, aldehyde-like.

EXAMPLE 2

4.3 g (0.05 mol) of diacetyl were added under an argon atmosphere to a solution of 3.85 g (0.05 mol) of cysteamine in 40 ml of methanol, whereby a warming of the mixture was observed. Thereafter, the mixture was heated to boiling under an argon atmosphere for 30 minutes. The solvent was removed on a rotary evaporator and the gas-chromatographically uniform crude product was subjected to short-path distillation in a bulb tube. There were thereby obtained 6 g (yield 83% of theory) of gas-chromatographically uniform 2-acetyl-2-methyl-thiazolidine of boiling point ₀.03 65°C; n_(D) ²⁰ = 1.5217. IR: ν_(max) = 1710, 1430, 1360, 1155, 1075, 855, 790 cm⁻ ¹. Odour: buttery, caramellous note, nutty, reminiscent of biscuit; flavour: diacetyl-like in the direction of caramel-butter, faintly nutty.

METHOD B: EXAMPLE 3

15.43 g (0.2 mol) of cysteamine and 29.0 g (0.2 mol) of isopropyl methyl ketone were treated with 200 ml of benzene and boiled under an inert gas atmosphere for 14 hours on a water-separator. The solution was concentrated on a rotary evaporator and filtered over 25 g of neutral aluminium oxide (activity I). The aluminium oxide was then flushed with ether. The filtrate was again concentrated and subsequently distilled under a high vacuum through a Widmer column. 22.51 g (yield 77% of theory) of 2-isopropyl-2-methylthiazolidine (n_(D) ²⁰ = 1.5085) passed over in a boiling range of 40°-42°C and at a pressure of 0.009 mm Hg. IR: ν_(max) = 1440, 1370, 790 cm⁻ ¹. Odour: camphorous, woody; flavour: greenish.

EXAMPLE 4

In an analogous manner to that described in the previous Examples, the thiazolidines listed in the following Table can be manufactured:

                                      Table                                        __________________________________________________________________________     Thiazolidine   B.p./mm Hg                                                                               n.sub.D.sup.20                                                                      Yield                                                                              IR (cm.sup.-.sup.1)                                                                    Olfactory interpretation             __________________________________________________________________________     2-(1-Hydroxyethyl)-2-                                                                         58°-62°C/0.05                                                              --   67% 1450, 1370,                                                                            Odour: burnt,                        methyl-thiazolidine                                                                           M.p. 35°-40°C                                                                       1105, 805                                                                              caramellous.                                                                   Flavour: buttery-fatty,                                                        faint burnt note.                    2-Acetyl-2-ethyl-                                                                             62°-64°C/0.04                                                              1.515                                                                               41% 1715, 1435,                                                                            Odour: burnt, meaty.                 thiazolidine/2-methyl-2-          1378, 850                                    propionyl-thiazolidine                    Flavour: nutty, meaty.               2-Ethyl-2-butyl-                                                                              45°-48°C/0.04                                                              1.5009                                                                              34% 1455, 1378,                                                                            Odour: pyrazine-like,                thiazolidine                      830     milk-like, caramellous.                                                        Flavour: weakly minty,                                                         (spearmint) weakly nutty.            2-Isobutyl-2-methyl-                                                                          50°-53°C/0.009                                                             1.5010                                                                              58% 1465, 1375,                                                                            Odour: green, flowery,               thiazolidine                      770     sweetish.                                                                      Flavour: greenish,                                                             ester-like, fruity.                  2-Secbutyl-thiazolidine                                                                       60°C/0.04                                                                         1.5059                                                                              75% 1460, 1380,                                                                            Odour: green, fruity,                                                  1190, 830                                                                              pyridine-like.                                                                 Flavour: weakly roasted,                                                       somewhat nut-like.                   2-(2-methylthioethyl)-                                                                        85°C/0.04                                                                         1.5645                                                                              69% 1440, 930,                                                                             Odour: potato-like,                  thiazolidine                      830     slightly roasted.                                                              Flavour: potato-like,                                                          slightly fatty.                      2-Butyl-thiazolidine                                                                          60°C/0.08                                                                         1.5031                                                                              63% 1455, 1185,                                                                            Odour: green-penetrating,                                               825, 790                                                                              bean-like, somewhat                                                            sulphurous note.                                                               Flavour: greenish,                                                             earthy, towards green                                                          tomatoes, raw potatoes.              2-Pentyl-thiazolidine                                                                         60°C/0.08                                                                         1.5002                                                                              83% 1455, 1190,                                                                            Odour: greenish, spicy-                                                 855, 810                                                                              earthy, vegetable-like                                                         towards                                                                        beans, asparagus, tomato).                                                     Flavour: strongly green,                                                       somewhat fatty, cucumber-                                                      like, towards asparagus                                                        or tomato.                           2-(2-Furyl)-thiazolidine                                                                      M.p.      --   84% 1450, 1160,                                                                            Odour: smoky, spicy,                                51.5°-58.5°C                                                                        1115, 930,                                                                             meaty, salami-like.                                                     840, 815                                                                              Flavour: mushroom-like,                                                        earthy.                              2-(2-Pyrrolyl)-                                                                               M.p. 110°-111°C                                                            --   72% 1455, 1440                                                                             Flavour: weakly flowery,             thiazolidine                      1190, 1100,                                                                            somewhat nut-like and                                                  1030, 915,                                                                             coffee-like.                                                            885, 825                                    2-Hydroxymethyl-2-methyl-                                                                     M.p. 38°-45°C                                                              --   55% 1455, 1375,                                                                            Odour: meaty, bread-                 thiazolidine                      1075, 805                                    like, hazel-nut like.                                                                                                    Flavour: nutty, meaty.               2-Ethoxycarbonyl-2-methyl-                                                                    93°-96°C/0.04                                                              1.4985                                                                              67% 1730, 1440,                                                                            Odour: spicy, greenish-              thiazolidine                      1180, 835                                                                              fruity.                                                                        Flavour: fruity,                                                               caramellous, sweetish,                                                         woody.                               2-Ethoxycarbonyl-                                                                             M.p. 27°-29°C                                                              --   90% 1740, 1450,                                                                            Odour: fruity, smoky,                thiazolidine                      1295, 820                                                                              pyrazine-like.                                                                 Flavour: weakly fruity,                                                        woody trace, somewhat                                                          smoky.                               2-Hydroxymethyl-                                                                              105°C/0.04                                                                        --   37% 1462, 1380,                                                                            Odour: green, woody,                 thiazolidine   M.p. 47°-48°C                                                                       1065, 950                                                                              roasted, spicy.                                                                Flavour: greenish,                                                             somewhat bitter.                     2,2-Tetramethylene-                                                                           48°-50°C/0.04                                                              1.5409                                                                              57% 1440, 1325,                                                                            Odour: greenish, fishy,              thiazolidine                      810     meaty.                                                                         Flavour: roasted,                                                              fishy, meaty.                        2,2-Pentamethylene-                                                                           57°-60°C/0.04                                                              --   76% 1445, 882,                                                                             Odour: pyrazine-like,                thiazolidine   M.p. 29°-31°C                                                                       798     smoky, nutty.                                                                  Flavour: earthy, nutty,                                                        broth-like.                          2-Methyl-2-propyl-                                                                            35°-36°C/0.04                                                              1.5040                                                                              67% 1460, 1375,                                                                            Odour: woody, fruity,                thiazolidine                      790     nutty-fatty.                                                                   Flavour: onion-like,                                                           fruity.                              2-Methyl-2-pentyl-                                                                            74°-75°C/0.04                                                              1.4979                                                                              60% 1460, 1375,                                                                            Odour: green, flowery,               thiazolidine                      790     sweet.                                                                         Flavour: flowery, sweet,                                                       greenish.                            2-Hexyl-2-methyl-                                                                             79°-81°C/0.04                                                              1.4955                                                                              60% 1460, 1375,                                                                            Odour: cocoa-like, fatty,            thiazolidine                      800     fruity.                                                                        Flavour: fatty-waxy,                                                           cocoa-like trace.                    2,2-Dipropyl-thiazolidine                                                                     60°-62°C/0.04                                                              1,4991                                                                              29% 1460, 1380,                                                                            Odour: pyrazine-like,                                                  795     ester-like, green, slight                                                      caramel note.                                                                  Flavour: greenish,                                                             sulphurous.                          2-Butyl-2-methyl-                                                                             43°-45°C/0.04                                                              1.5021                                                                              37% 1460, 1375,                                                                            Odour: ester-like, milk-             thiazolidine                       805, 785                                                                              like, green, slightly burnt                                                    Flavour: caramellous,                                                          nutty.                               2-Heptyl-thiazolidine                                                                         79°-81°C/0.04                                                              1.4959                                                                              72% 1460, 1380,                                                                            Odour: ester-like,                                                      840, 805                                                                              green, bean-pod like,                                                          ivy, slightly flowery.                                                         Flavour: aldehydic-fatty,                                                      greenish-flowery.                    2-Octyl-thiazolidine                                                                          98°-99°C/0.04                                                              1.4938                                                                              71% 1460, 1380,                                                                            Odour: pyrazine-like,                                                  810     meaty, roasted.                                                                Flavour: strong                                                                aldehydic-fatty, metallic.           2,2-Diethyl-thiazolidine                                                                      37°C/0.01                                                                         1.5086                                                                              75% 1460, 1375,                                                                            Odour: meaty, fishy,                                                   835     sardine-like, slightly fatty.                                                  Flavour: solvent-like                                                          (acetone).                           2-Benzyl-thiazolidine                                                                         80°C/0.06                                                                         --   38% 1605, 1500,                                                                            Odour: greenish,                                    M.p.               1460, 1190,                                                                            flowery, slightly                                   33.5°-34.5°C                                                                        1120, 805,                                                                             phenylacetaldehyde-like.                                                760, 705                                                                              Flavour: sweet, flowery                                                        such as phenyl-                                                                acetaldehyde.                        2,2-Dimethyl-thiazolidine                                                                     80°C/8                                                                            1.5085                                                                              84% 1440, 1360,                                                                            Odour: meat-, pyridine-                                                1115, 1060,                                                                            like, roasted,                                                         790     somewhat fatty.                                                                Flavour: pyrazine-like,                                                        somewhat meaty, slightly                                                       roasted, slightly                                                              bread-like.                          2-Propyl-thiazolidine                                                                         55°C/0.3                                                                          1.5081                                                                              72% 1460, 1190,                                                                            Odour: pungent,                                                         920, 810                                                                              pyridine-like, harsh                                                           radish-like, slightly                                                          metallic.                                                                      Flavour: pungent                                                               green, slightly caramellous.                                                   note, towards bread.                 2-Phenyl-thiazolidine                                                                         M.p. 109°-110°C                                                            --   90% 1495, 1450,                                                                            Odour: weakly greenish-                                                1180, 825                                                                              leafy, earthy.                                                                 Flavour: weakly greenish.            2-Hexyl-thiazolidine                                                                          65°C/0.08                                                                         1.4970                                                                              73% 1455, 1190,                                                                            Odour: green, towards                                                   930, 820                                                                              green beans, somewhat                                                          fatty note.                                                                    Flavour: strongly green,                                                       towards beans, somewhat                                                        fatty.                               2-Ethyl-thiazolidine                                                                          62°-63°C/11                                                                --   88% 1460, 1195,                                                                            Odour: pyridine-ammonia                                                 915, 835,                                                                             like, strong, slightly                                                 780     nutty background.                                                              Flavour: slightly fruity,                                                      after-taste: leeks,                                                            mustard-like.                        2-Ethyl-2-methyl-                                                                             50°C/0.07                                                                         1.5080                                                                              59% 1460, 1440,                                                                            Odour: pungent,                      thiazolidine                      1375, 1120, pyridine-like, towards                                             1090, 805,                                                                             fish, meat,                                                            775     camphorous background,                                                         woody.                                                                         Flavour: ammonia-like.               2-Ethyl-2-propyl-                                                                             69°-70°C/0.01                                                              1.5027                                                                              63% 3320, 1460,                                                                            Odour: spicy, slightly               thiazolidine                      1375, 1115,                                                                            milky.                                                                 825                                          2-Ethoxycarbonylmethyl-2-                                                                     69°-72°C/0.02                                                              1.5086                                                                              34% 3340, 1730,                                                                            Odour: ester-like,                   methyl-thiazolidine               1610, 1445,                                                                            sulphurous, green,                                                     1370, 1175                                                                             somewhat spicy.                      2-(2-Ethoxycarbonylethyl)-                                                                    101°-104°C/0.03                                                            1.5038                                                                              54% 3350, 1730,                                                                            Odour: sulphurous,                   2-methyl-thiazolidine             1445, 1375,                                                                            meat-like, sweetish.                                                   1180, 800                                    2-Methyl-2-nonyl-                                                                             108°-112°C/0.03                                                            1.4895                                                                              57% 3320, 1465,                                                                            Odour: slightly fish and             thiazolidine                      1375, 1135,                                                                            amine-like, tunny-like.                                                 790, 730                                    2-Dimethoxymethyl-                                                                            52°-55°C/0.01                                                              1.5027                                                                              49% 3340, 1440,                                                                            Odour: meat-like,                    thiazolidine                      1375, 1105,                                                                            slightly roasted.                                                      1090                                         2-Decyl-thiazolidine                                                                          115°-125°C/0.03                                                            --   14% 3300, 1465,                                                                            Odour: woody earthy,                                M.p. 25°-30°C                                                                        805, 715                                                                              quinoline-like.                      2-Acetoxymethyl-2-methyl-                                                                     70°-72°C/0.02                                                              1.5070                                                                              58% 3350, 1740,                                                                            Odour: roasted,                      thiazolidine                      1450, 1380,                                                                            spicy, peanut-like.                                                    1235, 1035                                   2-(1-Acetoxyethyl)-2-                                                                         66°-70°C/0.02                                                              1.5004                                                                              40% 3350, 1740,                                                                            Odour: sulphurous,                   methyl-thiazolidine               1445, 1370,                                                                            slightly burnt, kohlrabi.                                                      1240, 1055                           2,2-Bis(acetoxymethyl)-                                                                       122°--123°C/0.03                                                           1.5149                                                                              50% 3350, 1740,                                                                            Odour: spicy, roasted,               thiazolidine                      1440, 1375,                                                                            pyrazine-like,                                                         1235, 1015                                                                             bread-like.                                                                    Flavour: bread-like,                                                           somewhat burnt.                      2,2-Bis(ethoxycarbonyl)-                                                                      115°-117°C/0.04                                                            --   45% 3340, 1735,                                                                            Odour: sweet, fruity,                thiazolidine   M.p. 31°-33°C                                                                       1450, 1370,                                                                            somewhat burnt.                                                        1025                                         2-(3-Hydroxypropyl)-2-                                                                        109°-111°C/0.02                                                            1.5290                                                                              56% 3300, 1450,                                                                            Odour: roasted,                      methyl-thiazolidine                                                                           M.p. 23°C   1380, 1210,                                                                            burnt, sulphurous.                                                     1070                                         2-(2,2-Dimethoxyethyl)-2-                                                                     68°-71°C/0.02                                                              1.4978                                                                              40% 3360, 1445,                                                                            Odour: spicy, meat-                  methyl-thiazolidine               1375, 1125,                                                                            like, fatty, salami.                                                   1050, 790                                    2-Ethoxycarbonyl-2-(1-                                                                        105°-110°C/0.05                                                            1.4902                                                                              29% 3360, 1735,                                                                            Odour: roasted,                      ethoxycarbonyl-ethyl)-            1465, 1370,                                                                            peanut-like, bread-like.             thiazolidine                      1250, 1190                                                                             Flavour: bread-like.                 2-[2-(5-Methylthienyl)]-                                                                      M.p. 66°-67°C                                                                   31% 1445, 839,                                                                             Odour: spicy, green,                 thiazolidine                      805     slightly phenolic, celery-                                                     like.                                2-[2-(5-Methylfuryl)]-                                                                        M.p. 46°-48°C                                                                   38% 1456, 1178,                                                                            Odour: mushroom-like,                thiazolidine                      1160, 1023,                                                                            slightly roast.                                                        838                                          2-(2-Pyridyl)-thiazolidine                                                                    123°-124°C/0.3                                                                  54% 1476, 1457,                                                                            Odour: woody, cedarwood-                                               1436, 1186,                                                                            like, somewhat smoky,                                                  1002, 833,                                                                             meaty, sausage-like.                                                   790                                          2,2-Bis(ethoxycarbonyl-                                                                       126°-134°C/0.06                                                            1.4911                                                                              36% 3350, 1735                                                                             Odour: fatty, slightly               methyl)-thiazolidine              1470, 1370,                                                                            greenish, salami-like,                                                 1180, 1030                                                                             meaty.                                                                         Flavour: slightly                                                              greenish, mushroom-like,                                                       meaty.                               2-(4-Methyl-3-pentenyl)-                                                                      58°-62°C/0.01                                                              1.5209                                                                              47% 3300, 1670,                                                                            Odour: green, amine-                 thiazolidine                      1450, 1380,                                                                            like, vegetable-like,                                                  830     slightly flowery.                    2-[4-(2,2-Dimethyl-                                                                           84°-87°C/0.02                                                              1.5128                                                                              75% 3340, 1475,                                                                            Odour: sardine-like,                 dioxolanyl)]-thiazolidine         1375, 1210,                                                                            slightly roasted.                                                      1070, 850                                                                              Flavour: nutty-earthy,                                                         towards peanuts.                     2-(2-Thienyl)-thiazolidine                                                                    106°-107°C/0.35                                                                 47% 1450, 1235,                                                                            Odour: spicy, slightly                              M.p. 44°-46°C                                                                       1195, 1180,                                                                            sulphurous, smoky.                                                      929, 857,                                                                             Flavour: smoky, phenolic.                                              833                                          2-[2-(N-methyl-pyrrolyl)]-                                                                    105°-106°C/0.2                                                                  50% 1495, 1448,                                                                            Odour: slightly metallic,            thiazolidine                      1300, 1193,                                                                            fatty.                                                                  848, 790                                    __________________________________________________________________________

The following Examples illustrate typical odorant and/or flavouring compositions provided by the invention:

EXAMPLE A

    Composition (Smoke Aroma)                                                                         A          B                                                                 Parts by Weight                                               ______________________________________                                         Methylisoeugenol   0.5        0.5                                              Pyruvic acid       3.0        3.0                                              Heliotropin        3.0        3.0                                              Furfurol           5.0        5.0                                              Eugenol            5.0        5.0                                              Vanillin           9.0        9.0                                              Guaiacol           20.0       10.0                                             2,2-Pentamethylene-thiazolidine                                                                   --         10.0                                             Alcohol            954.5      954.5                                                               1000.0     1000.0                                           ______________________________________                                    

The partial replacement of guaiacol in aroma composition A by 2,2-pentamethylene-thiazolidine gives a more typical smoky note.

EXAMPLE B

    Composition (Licorice Aroma)                                                                      A          B                                                                 Parts by Weight                                               ______________________________________                                         Dimethylresorcin (10% alcohol)                                                                    2.0        2.0                                              Isobutylquinoline (10% alcohol)                                                                   5.0        5.0                                              Mousse de Chene (10% alcohol)                                                                     10.0       10.0                                             Corylone           30.0       30.0                                             Methylionone       60.0       60.0                                             Maltol             10.0       10.0                                             Anethol synth.     160.0      100.0                                            2,2-Dimethylthiazolidine                                                                          --         60.0                                             Alcohol            723.0      723.0                                                               1000.0     1000.0                                           ______________________________________                                    

The partial replacement of Anethol synth. in aroma composition A by 2,2-dimethylthiazolidine gives a slightly greenish, nut-like note which is strongly reminiscent of licorice.

EXAMPLE C

    Composition (Hazelnut Aroma)                                                                      A      B      C                                                                Parts by weight                                             __________________________________________________________________________     Maltol             2.0    2.0    2.0                                           Acetylmethylcarbinol                                                                              2.0    2.0    2.0                                           Acetophenone       3.0    3.0    3.0                                           Acetanisole        3.0    3.0    3.0                                           Furfurylmercaptan  5.0    5.0    5.0                                           Cinnamic acid amyl ester                                                       (10% in alcohol)   5.0    5.0    5.0                                           Vanillin           10.0   10.0   10.0                                          Diacetyl (10% in alcohol)                                                                         10.0   10.0   10.0                                          Aldehyde C 18      10.0   10.0   10.0                                          Phenylacetic acid amyl ester                                                   (10% in alcohol)   10.0   10.0   10.0                                          Phenylacetaldehyde 10.0   10.0   10.0                                          Corylone           15.0   15.0   15.0                                          Benzaldehyde       100.0  100.0  100.0                                         Dimethylresorcinol 350.0  300.0  270.0                                         2-Acetyl-2-ethyl-thiazolidine/                                                 2-methyl-2-propionyl-thiazolidine                                              mixture            --     50.0   --                                            2-Ethoxycarbonyl-2-methyl-                                                                        --     --     80.0                                          thiazolidine                                                                   Alcohol            465.0  465.0  465.0                                                            1000.0 1000.0 1000.0                                        __________________________________________________________________________

The partial replacement of dimethylresorcinol in aroma composition A by a 2-acetyl-2-ethyl-thiazolidine/2-methyl-2-propionyl-thiazolidine mixture or by 2-ethoxycarbonyl-2-methyl-thiazolidine gives a nut-like note which is strongly reminiscent of hazelnut.

EXAMPLE D

    Composition (Bean Aroma)                                                                         A      B      C                                                                Parts by Weight                                              __________________________________________________________________________     Methylchavicol (1% in alcohol)                                                                   0.5    0.5    0.5                                            Garlic (1% in alcohol)                                                                           2.0    2.0    2.0                                            Thymol (1% in alcohol)                                                                           0.5    0.5    0.5                                            Isobutyric acid piperonyl ester                                                (1% in alcohol)   3.0    3.0    3.0                                            Nona-2,6-dienal (1% in alcohol)                                                                  5.0    5.0    5.0                                            Acetic acid linalyl ester (1% in                                                                 5.0    5.0    5.0                                            alcohol)                                                                       3-Hexenyl-acetylacetate                                                                          10.0   10.0   10.0                                           2-(2-Methylthioethyl)-                                                         thiazolidine      --     1.0    --                                             2-Pentylthiazolidine                                                                             --     --     0.5                                            Alcohol           974.0  973.0  973.5                                                            1000.0 1000.0 1000.0                                         __________________________________________________________________________

The addition of 2-(2-methylthioethyl)-thiazolidine and/or 2-pentylthiazolidine to aroma composition A gives an intense vegetable-like note which is reminiscent of beans. 

We claim:
 1. 2-acetyl-2-methyl-thiazolidine. 